© 2015 American Chemical Society. A systematic computational study of the gas-phase adsorption of different amino-acid-analogues (AA-an's) on a (6,0) boron nitride nanotube (BNNT) and on a boron nitride monolayer (BNML) has been performed by means of B3LYP-D2∗ periodic calculations. The AA-an's are CH<inf>3</inf>-R molecules, where R represents functional groups present in amino acid side chains, i.e., OH, COOH, CONH<inf>2</inf>, NH<inf>2</inf>, imidazole, guanidine, phenyl, phenol, indole, and CONHCH<inf>3</inf>. On (6,0) BNNT, AA-an species containing N electron donor groups (i.e., R = NH<inf>2</inf>, imidazole, and guanidine) are strongly chemisorbed through dative interactions between the N atom of the AA-an and a B atom of the nanotube and present the largest adsorption energies (δE<inf>ads</inf>). For AA-an bearing aromatic rings (i.e., R = phenyl, phenol and indole) and R = CONHCH<inf>3</inf>, adsorption is driven by π-stacking interactions (with lower δE<inf>ads</inf> values than the previous group), while for AA-an with O electron donor groups and H-bonding donor groups (i.e., R = OH, COOH, and CONH<inf>2</inf>) adsorption is dictated by dispersion of moderate strength alongside weak dative and H-bond interactions, thus presenting the lowest δE<inf>ads</inf>. Significant differences are found on BNMLs. All adducts form by means of dispersion interactions of a different nature. The most stable adducts are those establishing π-stacking interactions, in which the π-systems of the AA-an's are aromatic rings (i.e., R = phenyl, phenol, indole, and imidazole). The AA-an group presenting the second most favorable δE<inf>ads</inf> also presents π-stacking interactions, but the π-system is a single double-bond (i.e., R = COOH, CONH<inf>2</inf>, guanidine, and CONHCH<inf>3</inf>), whereas for R = NH<inf>2</inf> and OH adsorption is due to CHπ interactions. On the basis of the computed adsorption energies, intrinsic affinity scales of the considered AA-an's for BN nanomaterials are proposed, which can give hints about those lateral chains responsible for the protein/BN nanomaterial interaction.